Slide fastener



Oct. 3, 1961 J. E. BURBANK 3,002,245

SLIDE FASTENER Filed July 3, 195a FIGJ. 12

22 H '23 IZ M/3 24 \25 Z0 2.9 85j/jro957j aFd INVENTOR.

JOHN E.BURBANK HIS ATTORNEYS nited States Pate fi C 3,002,245 PatentedOct. 3, 1961 3,002,245 SLIDE FASTENER John E. Burbank, Stamford, Conn.,assignor to Cue Fastener, lncorporatemstamford, Conn, a corporation ofNew York Filed July 3, 1958, Ser. No. 746,541 3 Claims. (Cl. 24-205. 15)

This invention relates to improvements in slide fasteners, and itrelates particularly to an improved type of fastener in which thefastening elements are continuous and include a plurality ofconvolutions or loops such as, for example, the helical or spiral typeof fastener.

Slide fasteners of the typereferred to above have problems in theirmanufacture and operation which are not encountered with the metallictooth or scoop-type of fastener. With these latter types of fasteners,for example, the slider which is used to open and close the fastener hasside flanges which bear against and ride along the outer metallic edgesof the fastener teeth. A metal to metal sliding contact is obtainedwhich permits the slider to move readilyalong the fastener withoutundesirably high friction and without danger of derailment of theslider.

With the coil or convoluted type of slide fastener formed of plastic, itis undesirable to have a metallic slider in direct contact with theplastic fastening elements for the reason that operation of the slidertends to wear and abrade the fastening elements. Moreover, the coillikeor convoluted form of such fasteners sometimes causes the slider to bederailed or disengaged from the fastening elements when the fastener issubjected to strong laterally directed forces tending to pull thefastening elements apart. For that reason, it is customary to secure tothe tapes adjacent the outer edges of the fastening elements, bead cordsformed of textile yarns against which the flanges of the slider bear.The bead cords form guide rails or tracks along which the slider movesout of contact with the'fasteningelements. The use of such bead cordsrequires the slider flanges to be fitted rather closely to the pieces ofmaterial to which the cords and the fastener members are secured inorder to prevent the cords from wed'ging in the slider and preventingits operation. When the flanges are too closely spaced, they rub againstthe tapes or other pieces of material to which the fastening elementsare secured, and result in undesirably rapid wear thereof.

The present invention involves a relationship between the slider, thebead cords and the fastening elements, which overcomes the disadvantagesnoted above, and results in a slide fastener which is opened and closedreadily and positively even under conditions where high lateral stressesare exerted on the fabric tending to pull the fastener elements apartand in which wear on the tapes or pieces of material, to which thefastener members are secured is reduced to a minimum.

More particularly, in accordance with the present invention, the slideris provided with grooves or recesses in the opposing surfaces of theinner and outer plates thereof to receive and engage the bead cords andthe fastener members, and guide the fastener members into and out ofmeshing relation, the recesses having their outer or lateral edgesspaced apart a distance considerably less than the distance between theouter or lateral edges of the bead cords when they are in anuncompressed condition and the fastener members are in meshed or closedrelation. By means of this relation, the bead cords are compressedinwardly, and the fastening elements adjacent thereto are urged togetherso that meshing thereof is assured even though large tension stressesare exerted on the tape members or pieces of material to which thefastener members are secured.

Surprisingly, compression of the bead cords by the restricted grooves inthe slider does not result in a markedly increased resistance tomovement of the slider of the slide fastener or substantially increasedwear on the bead cords. Moreover, due to the compression of the beadcords laterally, they are expanded somewhat in a plane at right anglesto the plane of the material to which they are secured, sothat theyprovide an increased lateral surface for engagement withthe flanges atthe edges of the slide fastener. As a result, the opposed edges of theflanges on the opposite sides of the tapes or pieces of material can bespaced more widely apart, thereby reducing wear on the tapes or piecesof material to which the fastening elements are attached.

For a better understanding ofthe present invention, reference may be hadto the accompanying drawing in which:

FIGURE v1 is a plan view of a portion of a slide fastener embodying thepresent invention;

-s sof FIGURE 1..

FIGURE Z is a view in cross-section taken on line The form of slidefastener chosen for purposes of illustration is a so-called spiralfastener, the type disclosed in the Schwartz application Serial No.346,380 filed April 2, 1953, now Patent'No. 2,858,592, dated November 4,1958. This type of fastener includes a pair of generally helical coils10 and 11 fonned of a filament of nylon or other similar plastic ofoblong crosssection. "It will be understood that other types of coils orcontinuous fastening elements having a series of loops or convolutionsmay also be provided, such as,'for ex- ,ample, the types of fasteningelements shown in the Schwartz application Serial No. 470,318 filedNovember i 22,1954 (now abandoned), and the Casson application SerialNo. 403,107 filed January 11, 1954, now Patent the tapes of.conventional slide fasteners. In order to provide a guidefor the slider14 used for opening and closing the fastener, a pair of bead cords 15and 16 are secured to the tape 13 on opposite sides thereof, adjacent rto and extending lengthwise of the coil ll thereon. Similar bead cords17 and 18 are secured to the tape 12 on opposite sides thereof adjacentthe coil 10 attached thereto.

As best shown in FIGURES l and 3, the slider 14 has an upper plate 19and a lower plate 20 which are normally disposed on opposite sides ofthe tapes 12 and 13 and the coils 10 and 11 and are connected insubstantially parallel relation at their leading end by means of anisland 21. At each lateral edge of the slider 14 are edge flanges 22,23, 24 and 25 which define the outer edges of grooves '26, 27, 28 and2.9 for receiving the bead cords 15 to 18, respectively.

The space between the grooves 26 to 29 is relieved somewhat to form arecess in which the meshed coils 10 and 11 are received. It will beunderstod that the grooves 26 and 27 diverge away from the grooves 28,29 on opposite sides of the island 21 but are in substantially parallelrelation at the opposite end of the slider 14. A slider of the typedescribed above is disclosed in my copending application Serial No.524,071 filed July 25, 1955, now Patent No. 2,909,824, dated October 27,1959.

The slider 14 diflers from that disclosed in my abovementionedapplication in that the spacing between the lateral edges of the grooves26 and 28 and the grooves 27 and 29 in the trailing portion of theslider, is between and of the distance d between the outer edges of thebeads '15 and 17 or the beads 16 and 18 as indicated by the legends onFIGURES 2 and 3. When the slider 14 is moved by means of its operatingtab 30 along the fastening members to the right as viewed in FIGURE 1,thediverging portions of the fastener members and 11 are broughttogether and directed into meshing relationship. If the recess in theslider 14 were big enough to receive the bead cords 15 to 18' withoutcompressing them, tension exerted transversely of the tapes 12 and 13would compress and move the cords 15, 16 away from the cords 17, 18, sothat the coils 10 and 11 would be pulled apart and prevented frommeshing properly. By making the distance narrower between the outerwalls of the grooves 26 and 28 and outer walls of the grooves 27 and 29,in accordance with the present invention, the bead cords 15 to 18 arecompressed inwardly by the slider toward the coils 10' and 11, and thecoils thereby are forced together in proper interlocking relation eventhough strong tension stresses may be exerted transversely of the tapes12 and 13 in opposition to the action of the slider in causing thefastening members to mesh.

Compression of the bead cords by the slider does not introduce enoughfriction to preclude the easy movement of the slider along the fasteningelements, but it does assure full and complete meshing of the coils 10and 11 in opposition to lateral stresses exerted thereon, as explainedabove. Accordingly, by proper dimensioning or proportioning of therecesses in the opposing faces of the slider as described above,substantially all of the disadvantages which have been encountered inthe operation of coil fasteners and other fasteners having continuousinterconnected loops .or convolutions are overcome.

It will beunderstood that the shape and dimensions of the slider andfastening elements can be modified and that the form of the inventiondescribed herein is illustrative.

I claim:

1. A slide fastener comprising a pair of continuous flexible fasteningelements composed of springy filaments, each having a plurality ofconvolutions, said elements beinga-dapted for meshing engagement, apiece of flexible material fixed to each fastening element, at least onecompressible guide bead secured to each piece of flexible material andextending adjacent to and lengthwise of said fastening element, saidbeads being disposed outwardly of said fastening element, and a sliderhaving internal grooves for receiving said fastening elements and beads,the spacing between the outer opposite sides of at least a 4 portion ofthe grooves for receiving the beads being about to of the spacingbetween the outer edges of said beads when the fastening elements are inmeshing engagement and said beads are unconfined.

2. A slide fastener comprising a pair of pieces of flexible material, anelongated flexible fastening element having a plurality of convolutionssecured to an edge of each piece of material, compressible bead cordssecured to opposite sides of each piece of material adjacent eachfastening element and extending substantially parallel therewith, aslider having a pair of spaced plates on opposite sides of saidfastening elements, pieces of material and bead cords, and an islandconnecting said plates and extending between said fastening elements,and internal recesses in said plates for receiving said fasteningelements and bead cords, a portion of the recess in each plate having amaximum width between about 85% and 95 of the distance between theoutermost sides of the bead cords received in said recess when saidfastening elements are engaged and the bead cords are unconfined.

3. A slide fastener comprising a pair of pieces of flexible material, anelongated flexible fastening element having a plurality of springyconvolutions secured adjacent to an edge of each piece of material,compressible guide elements secured to opposite sides of each piece ofmaterial adjacent each fastening element and extending substantiallyparallel therewith, a slider having a pair of spaced plates on oppositesides of said fastening elements, pieces of material and guide elements,an island connecting said plate and extending between said fasteningelements and flanges at the lateral edges of each plate extending towardsaid pieces of material for engaging the outer lateral surfaces of saidguide elements, portions of the flanges on each plate having a maximumspacing between about 85% and 95% of the distance between said outerlateral surfaces of the guide elements when said fastening elements areengaged and the guide elements are unconfined.

References Cited in the file of this patent UNITED STATES PATENTS2,497,821 Kohler Feb. 14, 1950 FOREIGN PATENTS 387,480 Great BritainFeb. 9, 1933 1,022,981 Germany Jan. 23, 1958 1,154,740 France Apr. 16,1958

